Generally this invention relates to an apparatus for flow-line treatment of articles in an artificial medium different from ambient atmosphere.
More specifically, the invention relates to an apparatus serving for flow-line treatment and coating articles, preferably three-dimensional parts, in an artificial gas medium or in vacuum. A feature of this apparatus is that operation of the treatment means and preset characteristics of the artificial medium are maintained much longer than it is necessary for treatment of a solitary article, and these articles are transported along the treatment zones through the locking chambers. Application of the apparatus of this type is well known for treatment of flat thin articles such as architectural glass, compact disk blanks or chips. However, apparatus of this type may be used most widely in the systems of deposition of metals or their compounds in high vacuum or an atmosphere of inert or reactive gases.
Another specification of the field of application is the apparatus for the flow-line treatment of certain number of articles, that is sets of parts fixed on a common carrier and transported as a whole during the process. Application of such apparatus is known for manufacture of small sized articles such as optical lenses, car light reflectors with antireflection or light reflecting coating mainly on one of the sides.
In a specific embodiment the proposed invention is an apparatus for flow-line treatment of the sets of articles on carriers in artificial and vacuum media, providing all-round metal or metal-containing coatings on three-dimensional articles such as plastic parts.
An apparatus for continuous metallizing of components, U.S. Pat. No. 5,622,564 of Apr. 22, 1997 was considered as the prior art. The apparatus comprises:
at least one vacuum working chamber provided with treatment means for processing of the articles;
means for maintaining the artificial atmosphere in the working chamber;
locks in ends of the vacuum working chamber;
a set of carriers for transportation the articles under treatment through at least one working chamber and the locks; and
loading and unloading devices in the ambient atmosphere and transport means for carriers.
In the prior art, the flow-line apparatus comprises the working chamber and locking chambers at its ends that all are arranged along a common horizontal line. The locking chambers with shutters are separated by gates between themselves and from the atmosphere. All chambers along their length are provided with rails, which form a general track for carriers travel, with travel drives, travel holdup stoppers, as well as with air evacuation and admittance means.
The working chamber is provided with a metal vapour source. Metal is supplied for evaporation in the form of wire. The carriers for components are made as carriages, comprising holders of the components, fixed to be rotating relative longitudinal horizontal axis and driven into revolution when stoppers delay carrier transportation.
As the design of the flow-line gates or of locks is not described in the prior art patent, it gives a ground to consider them in similar to known units, as for example described in EP-A-0 554 522 of Aug. 11, 1993.
Such unit comprises a stationary part in the form of opening and corresponding shutter, closing this opening.
The shutter is provided with means for effective travelling along the opening and force movement to deform resilient sealing, which is along the opening perimeter.
In this case the closed structure must resist significant forces arising at a pressure difference on the shutter. Pointed out circumstances are determined by the basic disadvantage of all similar unitsxe2x80x94their restricted operation speed (due to the movement character) and quick wearing out or the sealant exposed to constant changes of stress conditions within a significant part of elasticity range of the shutter material.
FR-A-1.496.205 describes an apparatus for flow-line treatment of articles under artificial atmosphere, the said apparatus comprising:
at least one vacuum working chamber provided with treatment means for processing of the articles;
means for maintaining the artificial atmosphere in the said working chamber;
locks in the ends of the vacuum working chamber;
transport means for transporting the articles through at least one working chamber and the locks;
loading and unloading devices in the ambient atmosphere, and
transportation means wherein each of the locks comprises a movable body, installed inside airtight shells, the body comprises at least one cavity;
the body is movable between a first position, in which the cavity is in connection with the first chamber and the transport means in the first chamber extends into the cavity, and a second position, in which the cavity is in connection with a second chamber, being located at the other side of the lock, while the transport means in the second chamber extend into the cavity; and wherein the gap between the shell and the body is an air gap seal.
In this prior art document both at the supply side and at the unload side a lock or a set of locks is required. This leads to a costly construction.
One object of the present invention is to provide such an apparatus which can be built at lower costs.
This aim is reached in that the body comprises at least two cavities, which are adjacent and similar and are provided with openings,
that each cavity is made with the volume for one, carrier with articles; and
that the transport means are made for simultaneous and antiparallel movement in both paired locking compartments.
This aim is reached in that the body comprises at least two cavities, which are adjacent and similar and are provided with openings,
that each cavity is made with the volume for one carrier with articles; and
that the transport means are made for simultaneous and antiparallel movement in both paired locking compartments.
The loading/unloading unit is in communication with the locking compartments of the locks at one position of the latter.
At the opposite position the adjacent locking compartments are communicated with the compartments of the next locks.
Another end of the apparatus is formed by a lock between two chambers with the highest vacuum in the system and has no output to the ambient atmosphere.